ASDA < TORA?

[richjb]

FAA stopped issuing waivers to the RSA standards a few years back and published Order 5200.8 in 1999 addressing the process to assess and address RSAs. Over the last several years, US airports subject to part 139 and FAA airport funding have worked to address substandard RSA. Some airports like, DCA and MDW were known to be problematic with respect to full RSA compliance. The availability of arresting systems EMAS have dramatically helped address these runway ends where airport geometry limits the space available for RSA extension. Simply reducing the ASDA is not always a solution, since by doing so one can make the runway not economically viable for air carrier operations.

To answer your question, RSA compliance is mandatory and FAA no issues waivers to the standard like they did in the past. All airports are required to come into full compliance to the maximum extent practicable and to develop a plan to do so. However, there will be some airports where full RSA compliance is not possible. Where DCA fits into this process, I don’t know.

Rich

[richjb]

Thanks for the explanation!

Most of the information that I have on ICAO runway standards is from Annex 14. Is there another Annex or other guidance provided by ICAO on airport design standards?

Thanks again,

Rich

[OverRun]

Rich,

Annex 14 is the main ICAO document on airport design standards. There is a handy link in the sticky’d threads at the top of ‘Tech Log’ to an electronic version of it.

There are some other ICAO documents but these are peripheral and 99.9% of airport design can be done using Annex 14. The other documents go into more detail in certain areas. I use mainly Parts 1-3 of the following:

Aerodrome Design Manual (Doc 9157)
Part 1 — Runways
Part 2 — Taxiways, Aprons and Holding Bays
Part 3 — Pavements
Part 4 — Visual Aids
Part 5 — Electrical Systems

Some other airport aspects are covered in the following, but some of them are quite dated and not of as much value:

Airport Planning Manual (Doc 9184)
Part 1 — Master Planning
Part 2 — Land Use and Environmental Control
Part 3 — Guidelines for Consultant/Construction Services

Airport Services Manual (Doc 9137)
Part 1 — Rescue and Fire Fighting
Part 2 — Pavement Surface Conditions
Part 3 — Bird Control and Reduction
Part 4 — Fog Dispersal (withdrawn)
Part 5 — Removal of Disabled Aircraft
Part 6 — Control of Obstacles
Part 7 — Airport Emergency Planning
Part 8 — Airport Operational Services
Part 9 — Airport Maintenance Practices

There is a heliport manual, but Annex 14 Vol 2 also covers heliports. The manual is:
Heliport Manual (Doc 9261).

Cheers
OverRun

[NotaLOT]

Hi All,

I am also from the ICAO part of the world. I have read through the explanations regarding ASDA sacrifice for RSA, but there is still one thing I don't understand. In such a constrained case surely increasing the longitudinal size of RSA requires not only a decrease in ASDA, but also in TORA?

[john_tullamarine]

not only a decrease in ASDA, but also in TORA?

Philosophically, ASDA is critical because the aircraft is on the ground throughout ASDR. However, the last part of TORR is airborne (by definition) so that may permit a lesser concern in regard to declared TORA.

Clearly, were the decrement to be significant, TORA would need to be revisited but, for the typical short distances involved, the aircraft still is going to be airborne for that remaining TORA delta.

[Sir George Cayley]

Standards and Recommended Practices. In ICAO language this means shall or should.

So in relation to RESA, the standard is 90m and the recommendation is 240m.

Some states take the recommended value as a requirement although often permit a distance between 90 & 240 if an aeronautical study shows the risk has been reduced to as low as reasonably practicable.

A cursory glance at some rejected take off overruns seems to point at 240m as a norm not 90m.

One area that needs addressing is aircrew electing to stop at either V1 or just above. The Brussels Kalitta 747 is a case in point. Does it suggest that some crew are so concerned that they prefer an overrun to exporting the problem into the air?

SGC

[JammedStab]

LAX notam for runway 24L which is normal length of 10,285'.

!LAX 12/299 LAX RWY 24L DECLARED DIST: TORA 9935FT TODA 9935FT ASDA 8935FT LDA 8362FT. 1512280125-1606012359EST

KLAX airport website info,

"Los Angeles International Airport (LAX) today closed Runway 7R-25L, the first of four runways currently scheduled for maintenance and federally-mandated Runway Safety Area (RSA) improvements. The one-runway-at-a-time construction work is scheduled to last through 2018 and may cause flight delays similar to those experienced during bad weather conditions.
The runway closures and/or temporary shortenings will allow crews to revise grades, construct new runway safety areas, lighting systems, and navigational aids to comply with federal RSA requirements. When runways are closed for RSA work, crews will take advantage of the time to also conduct runway maintenance and rehabilitation.

Following completion of the RSA projects, Los Angeles World Airports (LAWA) will perform additional runway and taxiway maintenance projects. These additional projects are currently in planning and the construction dates, runway closures and other impacts associated with these projects are still being determined.

Closures and/or shortening of LAX’s runways are anticipated to continue over the next three years and are scheduled as follows:

• Runway 7R-25L: March 2015 – April 2015

• Runway 6L-24R: June 2015 – October 2015

• Runway 6R-24L: November 2015 – October 2016

• Runway 7L-25R: October 2016 – June 2017

• Additional Runway Maintenance: Dates To Be Determined

Scheduled dates are subject to change."

[underfire]

For FAA land, the FAA document explaining the differences. Basically the mandated RSA is being put into place, either in reality or by moving the invisible lines..https://www.faa.gov/airports/airport...a/cert0905.pdf

In some cases, an airport operator may use declared distances to satisfy the requirement for a runway safety area off a particular runway end. This in effect would shorten the runway length available to be used for ASDA and LDA. (TORA and TODA are never reduced in this situation.) (emphasis added) In other cases, an airport operator may use declared distances different than the paved runway length to satisfy runway protection zone (RPZ) or runway object free area (ROFA) requirements, or to reflect a displaced threshold, clearway, or stopway. See the definitions in AC 150/5300-13 Appendix 14, except note that declared distances are to be listed for all runways at certificated airports, not limited to those cases where it is impracticable to provide the required RSA, ROFA, or RPZ as stated in the AC. Additionally, the contents of CERTALERT 00-03 (Stopway), as amended in accordance with this CERTALERT, is attached as a reminder of the criteria to use for designating a stopway.

Pilots and airplane operators’ performance engineers need this information for calculating their allowable takeoff and landing weights and speeds. Therefore, this information needs to be readily available.

The TODA does not take into account obstacles (other than those considered in meeting the RPZ, ROFA, and clearway requirements) that may be off the departure end of the runway. Therefore, the pilot is responsible for determining if the aircraft can clear those obstacles according to the applicable airplane operating regulations and airplane performance data.

[Omjeeprasad]

As per ICAO, Annex-14: Accelerate-stop Distance Available (ASDA) is "The length of the take-off run available (TORA) plus the length of the stopway, if provided". Which means that
ASDA = TORA + Stopway (If provided).

Hence, It is very clear that in any case the ASDA can not be less that the TORA of the associated RWY.

Cheers
Om Jee Prasad

[Sepp]

Originally Posted by Omjeeprasad

...
ASDA can not be less that the TORA of the associated RWY.

Cheers
Om Jee Prasad

Meanwhile, at KATL: Rwy 08L/26R ASDA 8800 ft., TORA 9000 ft.

[Smythe]

ASDA=TORA - stopway (if you need part of the runway as the stopway.)

8800=9000-200.

KPSP RW13R: TORA:10000 TODA:10000 ASDA:9857 LDA:6857

[Musket90]

Whoever calculated the ASDA distance to be less than TORA is wrong. ASDA value is either equal to TORA (when no stopway provided) or more (when stopway is provided). The origin of the RESA starts 60m (runway strip) beyond the end of TORA or ASDA. Check ICAO Annex 14.

[Sepp]

Originally Posted by Musket90

Whoever calculated the ASDA distance to be less than TORA is wrong. ASDA value is either equal to TORA (when no stopway provided) or more (when stopway is provided).
...

Not according to the FAA AIM. Witness this diagram. Note the figures for rwy 09 and associated explanation. ASDA can be shorter than TORA if part of the runway has to be "used up" to satisfy one or more design requirements.

[Smythe]

one should note that the RW examples given are FAA, not ICAO.

[pattern_is_full]

Of note: ATL 08L/26R has HOLD markings right across the runway 400 feet in from the threshold keys at each end. ==============

https://www.google.com/maps/place/Ha...!4d-84.4277001

Similar to LAHSO markings (except no crossing runway in existence). No idea why (any local knowledge?).

What effect do such markings have on ASDA calculation?

NB: KATL 09R/27L has similar markings - and also has ASDA < TORA (slightly).

[Musket90]

Interesting. These 08L/26R markings are taxiway/runway holding position "pattern A" markings and it appears they have associated signs. I can only think that they are provided for ATC to hold an aircraft at these positions on the runway to give priority to aircraft on the crossing taxiway at the runway ends. An odd situation as runway movements would normally have priority over crossing traffic, unless the runway is sometimes used as a taxiway.

Regarding TORA/ASDA, maybe FAA file a difference with ICAO on this but I don't understand the logic.

[Smythe]

In the case of the USA, the FAA Airport Design requirements specify the minimum dimensions of a ‘Runway Safety Area’ which includes the Runway Strip defined by ICAO. Since 2002, these requirements have included a Runway Safety Area at each end of a runway which takes account of the direction of runway use when specifying the minimum length of the runway end element. The basic standard is defined for instrument runways used by transport aircraft and any such runway with an ‘approach visibility minima’ of less than 1200 metres and is 300 metres for the overrun case and 180 metres for the undershoot case. It is permissible to reduce the overrun case to 180 metres if the runway has either instrument or visual vertical guidance aids and an Engineered Materials Arresting System (EMAS) which can stop an aircraft which leaves the end of the runway at up to 70 kts groundspeed is provided.

It can be seen that the FAA overrun requirement (300 metres) is equivalent to the ICAO RESA Recommended Practice plus the required Runway Strip (also totalling 300 metres) but that the FAA undershoot requirement (180 metres) is only slightly more than the ICAO RESA Standard plus the required runway strip (totalling 150 metres).